/* tmp401.c
   *
   * Copyright (C) 2007,2008 Hans de Goede <hdegoede@redhat.com>

   * Preliminary tmp411 support by:
   * Gabriel Konat, Sander Leget, Wouter Willems
   * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>

   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  /*
   * Driver for the Texas Instruments TMP401 SMBUS temperature sensor IC.
   *
   * Note this IC is in some aspect similar to the LM90, but it has quite a
   * few differences too, for example the local temp has a higher resolution
   * and thus has 16 bits registers for its value and limit instead of 8 bits.
   */
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/jiffies.h>
  #include <linux/i2c.h>
  #include <linux/hwmon.h>
  #include <linux/hwmon-sysfs.h>
  #include <linux/err.h>
  #include <linux/mutex.h>
  #include <linux/sysfs.h>
  
  /* Addresses to scan */
  static const unsigned short normal_i2c[] = { 0x4c, I2C_CLIENT_END };

  enum chips { tmp401, tmp411 };

  
  /*
   * The TMP401 registers, note some registers have different addresses for
   * reading and writing
   */
  #define TMP401_STATUS				0x02
  #define TMP401_CONFIG_READ			0x03
  #define TMP401_CONFIG_WRITE			0x09
  #define TMP401_CONVERSION_RATE_READ		0x04
  #define TMP401_CONVERSION_RATE_WRITE		0x0A
  #define TMP401_TEMP_CRIT_HYST			0x21
  #define TMP401_CONSECUTIVE_ALERT		0x22
  #define TMP401_MANUFACTURER_ID_REG		0xFE
  #define TMP401_DEVICE_ID_REG			0xFF

  #define TMP411_N_FACTOR_REG			0x18

  
  static const u8 TMP401_TEMP_MSB[2]			= { 0x00, 0x01 };
  static const u8 TMP401_TEMP_LSB[2]			= { 0x15, 0x10 };
  static const u8 TMP401_TEMP_LOW_LIMIT_MSB_READ[2]	= { 0x06, 0x08 };
  static const u8 TMP401_TEMP_LOW_LIMIT_MSB_WRITE[2]	= { 0x0C, 0x0E };
  static const u8 TMP401_TEMP_LOW_LIMIT_LSB[2]		= { 0x17, 0x14 };
  static const u8 TMP401_TEMP_HIGH_LIMIT_MSB_READ[2]	= { 0x05, 0x07 };
  static const u8 TMP401_TEMP_HIGH_LIMIT_MSB_WRITE[2]	= { 0x0B, 0x0D };
  static const u8 TMP401_TEMP_HIGH_LIMIT_LSB[2]		= { 0x16, 0x13 };
  /* These are called the THERM limit / hysteresis / mask in the datasheet */
  static const u8 TMP401_TEMP_CRIT_LIMIT[2]		= { 0x20, 0x19 };

  static const u8 TMP411_TEMP_LOWEST_MSB[2]		= { 0x30, 0x34 };
  static const u8 TMP411_TEMP_LOWEST_LSB[2]		= { 0x31, 0x35 };
  static const u8 TMP411_TEMP_HIGHEST_MSB[2]		= { 0x32, 0x36 };
  static const u8 TMP411_TEMP_HIGHEST_LSB[2]		= { 0x33, 0x37 };

  /* Flags */
  #define TMP401_CONFIG_RANGE		0x04
  #define TMP401_CONFIG_SHUTDOWN		0x40
  #define TMP401_STATUS_LOCAL_CRIT		0x01
  #define TMP401_STATUS_REMOTE_CRIT		0x02
  #define TMP401_STATUS_REMOTE_OPEN		0x04
  #define TMP401_STATUS_REMOTE_LOW		0x08
  #define TMP401_STATUS_REMOTE_HIGH		0x10
  #define TMP401_STATUS_LOCAL_LOW		0x20
  #define TMP401_STATUS_LOCAL_HIGH		0x40
  
  /* Manufacturer / Device ID's */
  #define TMP401_MANUFACTURER_ID			0x55
  #define TMP401_DEVICE_ID			0x11

  #define TMP411_DEVICE_ID			0x12

  
  /*

   * Driver data (common to all clients)
   */
  
  static const struct i2c_device_id tmp401_id[] = {
  	{ "tmp401", tmp401 },

  	{ "tmp411", tmp411 },

  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, tmp401_id);

  /*
   * Client data (each client gets its own)
   */
  
  struct tmp401_data {
  	struct device *hwmon_dev;
  	struct mutex update_lock;
  	char valid; /* zero until following fields are valid */
  	unsigned long last_updated; /* in jiffies */

  	enum chips kind;

  
  	/* register values */
  	u8 status;
  	u8 config;
  	u16 temp[2];
  	u16 temp_low[2];
  	u16 temp_high[2];
  	u8 temp_crit[2];
  	u8 temp_crit_hyst;

  	u16 temp_lowest[2];
  	u16 temp_highest[2];

  };
  
  /*
   * Sysfs attr show / store functions
   */
  
  static int tmp401_register_to_temp(u16 reg, u8 config)
  {
  	int temp = reg;
  
  	if (config & TMP401_CONFIG_RANGE)
  		temp -= 64 * 256;
  
  	return (temp * 625 + 80) / 160;
  }
  
  static u16 tmp401_temp_to_register(long temp, u8 config)
  {
  	if (config & TMP401_CONFIG_RANGE) {
  		temp = SENSORS_LIMIT(temp, -64000, 191000);
  		temp += 64000;
  	} else
  		temp = SENSORS_LIMIT(temp, 0, 127000);
  
  	return (temp * 160 + 312) / 625;
  }
  
  static int tmp401_crit_register_to_temp(u8 reg, u8 config)
  {
  	int temp = reg;
  
  	if (config & TMP401_CONFIG_RANGE)
  		temp -= 64;
  
  	return temp * 1000;
  }
  
  static u8 tmp401_crit_temp_to_register(long temp, u8 config)
  {
  	if (config & TMP401_CONFIG_RANGE) {
  		temp = SENSORS_LIMIT(temp, -64000, 191000);
  		temp += 64000;
  	} else
  		temp = SENSORS_LIMIT(temp, 0, 127000);
  
  	return (temp + 500) / 1000;
  }

  static struct tmp401_data *tmp401_update_device_reg16(
  	struct i2c_client *client, struct tmp401_data *data)
  {
  	int i;
  
  	for (i = 0; i < 2; i++) {
  		/*
  		 * High byte must be read first immediately followed
  		 * by the low byte
  		 */
  		data->temp[i] = i2c_smbus_read_byte_data(client,
  			TMP401_TEMP_MSB[i]) << 8;
  		data->temp[i] |= i2c_smbus_read_byte_data(client,
  			TMP401_TEMP_LSB[i]);
  		data->temp_low[i] = i2c_smbus_read_byte_data(client,
  			TMP401_TEMP_LOW_LIMIT_MSB_READ[i]) << 8;
  		data->temp_low[i] |= i2c_smbus_read_byte_data(client,
  			TMP401_TEMP_LOW_LIMIT_LSB[i]);
  		data->temp_high[i] = i2c_smbus_read_byte_data(client,
  			TMP401_TEMP_HIGH_LIMIT_MSB_READ[i]) << 8;
  		data->temp_high[i] |= i2c_smbus_read_byte_data(client,
  			TMP401_TEMP_HIGH_LIMIT_LSB[i]);
  		data->temp_crit[i] = i2c_smbus_read_byte_data(client,
  			TMP401_TEMP_CRIT_LIMIT[i]);
  
  		if (data->kind == tmp411) {
  			data->temp_lowest[i] = i2c_smbus_read_byte_data(client,
  				TMP411_TEMP_LOWEST_MSB[i]) << 8;
  			data->temp_lowest[i] |= i2c_smbus_read_byte_data(
  				client, TMP411_TEMP_LOWEST_LSB[i]);
  
  			data->temp_highest[i] = i2c_smbus_read_byte_data(
  				client, TMP411_TEMP_HIGHEST_MSB[i]) << 8;
  			data->temp_highest[i] |= i2c_smbus_read_byte_data(
  				client, TMP411_TEMP_HIGHEST_LSB[i]);
  		}
  	}
  	return data;
  }
  
  static struct tmp401_data *tmp401_update_device(struct device *dev)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct tmp401_data *data = i2c_get_clientdata(client);
  
  	mutex_lock(&data->update_lock);
  
  	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
  		data->status = i2c_smbus_read_byte_data(client, TMP401_STATUS);
  		data->config = i2c_smbus_read_byte_data(client,
  						TMP401_CONFIG_READ);
  		tmp401_update_device_reg16(client, data);
  
  		data->temp_crit_hyst = i2c_smbus_read_byte_data(client,
  						TMP401_TEMP_CRIT_HYST);
  
  		data->last_updated = jiffies;
  		data->valid = 1;
  	}
  
  	mutex_unlock(&data->update_lock);
  
  	return data;
  }

  static ssize_t show_temp_value(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct tmp401_data *data = tmp401_update_device(dev);
  
  	return sprintf(buf, "%d
  ",
  		tmp401_register_to_temp(data->temp[index], data->config));
  }
  
  static ssize_t show_temp_min(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct tmp401_data *data = tmp401_update_device(dev);
  
  	return sprintf(buf, "%d
  ",
  		tmp401_register_to_temp(data->temp_low[index], data->config));
  }
  
  static ssize_t show_temp_max(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct tmp401_data *data = tmp401_update_device(dev);
  
  	return sprintf(buf, "%d
  ",
  		tmp401_register_to_temp(data->temp_high[index], data->config));
  }
  
  static ssize_t show_temp_crit(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct tmp401_data *data = tmp401_update_device(dev);
  
  	return sprintf(buf, "%d
  ",
  			tmp401_crit_register_to_temp(data->temp_crit[index],
  							data->config));
  }
  
  static ssize_t show_temp_crit_hyst(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	int temp, index = to_sensor_dev_attr(devattr)->index;
  	struct tmp401_data *data = tmp401_update_device(dev);
  
  	mutex_lock(&data->update_lock);
  	temp = tmp401_crit_register_to_temp(data->temp_crit[index],
  						data->config);
  	temp -= data->temp_crit_hyst * 1000;
  	mutex_unlock(&data->update_lock);
  
  	return sprintf(buf, "%d
  ", temp);
  }

  static ssize_t show_temp_lowest(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct tmp401_data *data = tmp401_update_device(dev);
  
  	return sprintf(buf, "%d
  ",
  		tmp401_register_to_temp(data->temp_lowest[index],
  					data->config));
  }
  
  static ssize_t show_temp_highest(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct tmp401_data *data = tmp401_update_device(dev);
  
  	return sprintf(buf, "%d
  ",
  		tmp401_register_to_temp(data->temp_highest[index],
  					data->config));
  }

  static ssize_t show_status(struct device *dev,
  	struct device_attribute *devattr, char *buf)
  {
  	int mask = to_sensor_dev_attr(devattr)->index;
  	struct tmp401_data *data = tmp401_update_device(dev);
  
  	if (data->status & mask)
  		return sprintf(buf, "1
  ");
  	else
  		return sprintf(buf, "0
  ");
  }
  
  static ssize_t store_temp_min(struct device *dev, struct device_attribute
  	*devattr, const char *buf, size_t count)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct tmp401_data *data = tmp401_update_device(dev);
  	long val;
  	u16 reg;

  	if (kstrtol(buf, 10, &val))

  		return -EINVAL;
  
  	reg = tmp401_temp_to_register(val, data->config);
  
  	mutex_lock(&data->update_lock);
  
  	i2c_smbus_write_byte_data(to_i2c_client(dev),
  		TMP401_TEMP_LOW_LIMIT_MSB_WRITE[index], reg >> 8);
  	i2c_smbus_write_byte_data(to_i2c_client(dev),
  		TMP401_TEMP_LOW_LIMIT_LSB[index], reg & 0xFF);
  
  	data->temp_low[index] = reg;
  
  	mutex_unlock(&data->update_lock);
  
  	return count;
  }
  
  static ssize_t store_temp_max(struct device *dev, struct device_attribute
  	*devattr, const char *buf, size_t count)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct tmp401_data *data = tmp401_update_device(dev);
  	long val;
  	u16 reg;

  	if (kstrtol(buf, 10, &val))

  		return -EINVAL;
  
  	reg = tmp401_temp_to_register(val, data->config);
  
  	mutex_lock(&data->update_lock);
  
  	i2c_smbus_write_byte_data(to_i2c_client(dev),
  		TMP401_TEMP_HIGH_LIMIT_MSB_WRITE[index], reg >> 8);
  	i2c_smbus_write_byte_data(to_i2c_client(dev),
  		TMP401_TEMP_HIGH_LIMIT_LSB[index], reg & 0xFF);
  
  	data->temp_high[index] = reg;
  
  	mutex_unlock(&data->update_lock);
  
  	return count;
  }
  
  static ssize_t store_temp_crit(struct device *dev, struct device_attribute
  	*devattr, const char *buf, size_t count)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct tmp401_data *data = tmp401_update_device(dev);
  	long val;
  	u8 reg;

  	if (kstrtol(buf, 10, &val))

  		return -EINVAL;
  
  	reg = tmp401_crit_temp_to_register(val, data->config);
  
  	mutex_lock(&data->update_lock);
  
  	i2c_smbus_write_byte_data(to_i2c_client(dev),
  		TMP401_TEMP_CRIT_LIMIT[index], reg);
  
  	data->temp_crit[index] = reg;
  
  	mutex_unlock(&data->update_lock);
  
  	return count;
  }
  
  static ssize_t store_temp_crit_hyst(struct device *dev, struct device_attribute
  	*devattr, const char *buf, size_t count)
  {
  	int temp, index = to_sensor_dev_attr(devattr)->index;
  	struct tmp401_data *data = tmp401_update_device(dev);
  	long val;
  	u8 reg;

  	if (kstrtol(buf, 10, &val))

  		return -EINVAL;
  
  	if (data->config & TMP401_CONFIG_RANGE)
  		val = SENSORS_LIMIT(val, -64000, 191000);
  	else
  		val = SENSORS_LIMIT(val, 0, 127000);
  
  	mutex_lock(&data->update_lock);
  	temp = tmp401_crit_register_to_temp(data->temp_crit[index],
  						data->config);
  	val = SENSORS_LIMIT(val, temp - 255000, temp);
  	reg = ((temp - val) + 500) / 1000;
  
  	i2c_smbus_write_byte_data(to_i2c_client(dev),
  		TMP401_TEMP_CRIT_HYST, reg);
  
  	data->temp_crit_hyst = reg;
  
  	mutex_unlock(&data->update_lock);
  
  	return count;
  }

  /*
   * Resets the historical measurements of minimum and maximum temperatures.
   * This is done by writing any value to any of the minimum/maximum registers
   * (0x30-0x37).
   */
  static ssize_t reset_temp_history(struct device *dev,
  	struct device_attribute	*devattr, const char *buf, size_t count)
  {
  	long val;

  	if (kstrtol(buf, 10, &val))

  		return -EINVAL;
  
  	if (val != 1) {
  		dev_err(dev, "temp_reset_history value %ld not"
  			" supported. Use 1 to reset the history!
  ", val);
  		return -EINVAL;
  	}
  	i2c_smbus_write_byte_data(to_i2c_client(dev),
  		TMP411_TEMP_LOWEST_MSB[0], val);
  
  	return count;
  }

  static struct sensor_device_attribute tmp401_attr[] = {

  	SENSOR_ATTR(temp1_input, S_IRUGO, show_temp_value, NULL, 0),
  	SENSOR_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp_min,
  		    store_temp_min, 0),
  	SENSOR_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
  		    store_temp_max, 0),
  	SENSOR_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp_crit,
  		    store_temp_crit, 0),
  	SENSOR_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp_crit_hyst,

  		    store_temp_crit_hyst, 0),

  	SENSOR_ATTR(temp1_min_alarm, S_IRUGO, show_status, NULL,

  		    TMP401_STATUS_LOCAL_LOW),

  	SENSOR_ATTR(temp1_max_alarm, S_IRUGO, show_status, NULL,

  		    TMP401_STATUS_LOCAL_HIGH),

  	SENSOR_ATTR(temp1_crit_alarm, S_IRUGO, show_status, NULL,

  		    TMP401_STATUS_LOCAL_CRIT),

  	SENSOR_ATTR(temp2_input, S_IRUGO, show_temp_value, NULL, 1),
  	SENSOR_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp_min,
  		    store_temp_min, 1),
  	SENSOR_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_max,
  		    store_temp_max, 1),
  	SENSOR_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp_crit,
  		    store_temp_crit, 1),
  	SENSOR_ATTR(temp2_crit_hyst, S_IRUGO, show_temp_crit_hyst, NULL, 1),
  	SENSOR_ATTR(temp2_fault, S_IRUGO, show_status, NULL,

  		    TMP401_STATUS_REMOTE_OPEN),

  	SENSOR_ATTR(temp2_min_alarm, S_IRUGO, show_status, NULL,

  		    TMP401_STATUS_REMOTE_LOW),

  	SENSOR_ATTR(temp2_max_alarm, S_IRUGO, show_status, NULL,

  		    TMP401_STATUS_REMOTE_HIGH),

  	SENSOR_ATTR(temp2_crit_alarm, S_IRUGO, show_status, NULL,

  		    TMP401_STATUS_REMOTE_CRIT),
  };
  
  /*

   * Additional features of the TMP411 chip.
   * The TMP411 stores the minimum and maximum
   * temperature measured since power-on, chip-reset, or
   * minimum and maximum register reset for both the local
   * and remote channels.
   */
  static struct sensor_device_attribute tmp411_attr[] = {

  	SENSOR_ATTR(temp1_highest, S_IRUGO, show_temp_highest, NULL, 0),
  	SENSOR_ATTR(temp1_lowest, S_IRUGO, show_temp_lowest, NULL, 0),
  	SENSOR_ATTR(temp2_highest, S_IRUGO, show_temp_highest, NULL, 1),
  	SENSOR_ATTR(temp2_lowest, S_IRUGO, show_temp_lowest, NULL, 1),
  	SENSOR_ATTR(temp_reset_history, S_IWUSR, NULL, reset_temp_history, 0),

  };
  
  /*

   * Begin non sysfs callback code (aka Real code)
   */
  
  static void tmp401_init_client(struct i2c_client *client)
  {
  	int config, config_orig;
  
  	/* Set the conversion rate to 2 Hz */
  	i2c_smbus_write_byte_data(client, TMP401_CONVERSION_RATE_WRITE, 5);
  
  	/* Start conversions (disable shutdown if necessary) */
  	config = i2c_smbus_read_byte_data(client, TMP401_CONFIG_READ);
  	if (config < 0) {
  		dev_warn(&client->dev, "Initialization failed!
  ");
  		return;
  	}
  
  	config_orig = config;
  	config &= ~TMP401_CONFIG_SHUTDOWN;
  
  	if (config != config_orig)
  		i2c_smbus_write_byte_data(client, TMP401_CONFIG_WRITE, config);
  }

  static int tmp401_detect(struct i2c_client *client,

  			 struct i2c_board_info *info)
  {

  	enum chips kind;

  	struct i2c_adapter *adapter = client->adapter;

  	u8 reg;

  
  	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
  		return -ENODEV;
  
  	/* Detect and identify the chip */

  	reg = i2c_smbus_read_byte_data(client, TMP401_MANUFACTURER_ID_REG);
  	if (reg != TMP401_MANUFACTURER_ID)
  		return -ENODEV;

  	reg = i2c_smbus_read_byte_data(client, TMP401_DEVICE_ID_REG);

  	switch (reg) {
  	case TMP401_DEVICE_ID:
  		kind = tmp401;
  		break;
  	case TMP411_DEVICE_ID:
  		kind = tmp411;
  		break;
  	default:
  		return -ENODEV;

  	}

  
  	reg = i2c_smbus_read_byte_data(client, TMP401_CONFIG_READ);
  	if (reg & 0x1b)
  		return -ENODEV;
  
  	reg = i2c_smbus_read_byte_data(client, TMP401_CONVERSION_RATE_READ);
  	/* Datasheet says: 0x1-0x6 */
  	if (reg > 15)
  		return -ENODEV;

  	strlcpy(info->type, tmp401_id[kind].name, I2C_NAME_SIZE);

  
  	return 0;
  }

  static int tmp401_remove(struct i2c_client *client)
  {
  	struct tmp401_data *data = i2c_get_clientdata(client);
  	int i;
  
  	if (data->hwmon_dev)
  		hwmon_device_unregister(data->hwmon_dev);
  
  	for (i = 0; i < ARRAY_SIZE(tmp401_attr); i++)
  		device_remove_file(&client->dev, &tmp401_attr[i].dev_attr);
  
  	if (data->kind == tmp411) {
  		for (i = 0; i < ARRAY_SIZE(tmp411_attr); i++)
  			device_remove_file(&client->dev,
  					   &tmp411_attr[i].dev_attr);
  	}
  
  	kfree(data);
  	return 0;
  }

  static int tmp401_probe(struct i2c_client *client,
  			const struct i2c_device_id *id)
  {
  	int i, err = 0;
  	struct tmp401_data *data;

  	const char *names[] = { "TMP401", "TMP411" };

  
  	data = kzalloc(sizeof(struct tmp401_data), GFP_KERNEL);
  	if (!data)
  		return -ENOMEM;
  
  	i2c_set_clientdata(client, data);
  	mutex_init(&data->update_lock);

  	data->kind = id->driver_data;

  
  	/* Initialize the TMP401 chip */
  	tmp401_init_client(client);
  
  	/* Register sysfs hooks */
  	for (i = 0; i < ARRAY_SIZE(tmp401_attr); i++) {
  		err = device_create_file(&client->dev,
  					 &tmp401_attr[i].dev_attr);
  		if (err)
  			goto exit_remove;
  	}

  	/* Register aditional tmp411 sysfs hooks */
  	if (data->kind == tmp411) {
  		for (i = 0; i < ARRAY_SIZE(tmp411_attr); i++) {
  			err = device_create_file(&client->dev,
  						 &tmp411_attr[i].dev_attr);
  			if (err)
  				goto exit_remove;
  		}
  	}

  	data->hwmon_dev = hwmon_device_register(&client->dev);
  	if (IS_ERR(data->hwmon_dev)) {
  		err = PTR_ERR(data->hwmon_dev);
  		data->hwmon_dev = NULL;
  		goto exit_remove;
  	}

  	dev_info(&client->dev, "Detected TI %s chip
  ", names[data->kind]);

  
  	return 0;
  
  exit_remove:
  	tmp401_remove(client); /* will also free data for us */
  	return err;
  }

  static struct i2c_driver tmp401_driver = {
  	.class		= I2C_CLASS_HWMON,
  	.driver = {
  		.name	= "tmp401",
  	},
  	.probe		= tmp401_probe,
  	.remove		= tmp401_remove,
  	.id_table	= tmp401_id,
  	.detect		= tmp401_detect,
  	.address_list	= normal_i2c,
  };

  
  static int __init tmp401_init(void)
  {
  	return i2c_add_driver(&tmp401_driver);
  }
  
  static void __exit tmp401_exit(void)
  {
  	i2c_del_driver(&tmp401_driver);
  }
  
  MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
  MODULE_DESCRIPTION("Texas Instruments TMP401 temperature sensor driver");
  MODULE_LICENSE("GPL");
  
  module_init(tmp401_init);
  module_exit(tmp401_exit);